Correct Option: A

Locked jaw syndrome is a disorder that is related to our jaw joint. It causes severe pain and sometimes cannot open the mouth. Tetanus, commonly called locked jaw, is a bacterial disease that affects the nervous system. Persons who have not been vaccinated adequately against tetanus are the most likely to get the disease. Tetanus occurs more often in older people who have not received adequate booster doses of vaccine and in agricultural workers where contact with animal manure is more likely. A common first sign of tetanus is muscular stiffness in the jaw (lockjaw), followed by stiffness of the neck, difficulty in swallowing, rigidity of abdominal muscles, and spasms.